Method of producing a gang of nailing means from sheet metal



A. DUBlNl Feb. 23, 1965 METHOD OF PRODUCING A GANG OF NAILING MEANS FROM SHEET METAL 3 Sheets-$heet 1 Filed June 28. 1960 INVENTOR. W BY A. DUBINI Feb. 23, 1965 METHOD OF PRODUCING A GANG OF NAILING MEANS FROM SHEET METAL 3 Sheets-Sheet 2 Filed June 28, 1960 INVENTOR.

A. DUBINI Feb. 23, 1965 7 METHOD OF PRODUCING A GANG OF NAILING MEANS FROM SHEET METAL 3 Sheets-Sheet 3 Filed June 28, 1960 JNVENTOR.

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airazrak Patented Feb. 23, 1965 3,170,279 METHOD F PRUDUCING A GANG 0F NAILING MEANS FROM SEEET METAL Antonio Dubini, Santo Stefano, Lecco, Italy Filed June 28, 1960, Ser. No. 39,397 Claims priority, application Italy, July 18, 1957,

9 575,329; July 3, 1959, 11,266/59 7 Claims. ((1159-77) This application is a continuation-in-part of my application Serial No. 729,207, filed April 17, 1958, now abandoned.

This invention relates to manufacture of nailing means constructed from sheet metal and more particularly to a gang or clip of such nailing means adapted for use with a nail driving device arranged with a magazine for a gang 7 of nailing means, means to feed the gang of nailing means longitudinally of the magazine and successively position the leading nailing means in the path of movement of a reciprocatory hammer or nail driver to successively drive each of the nailing means included in said gang.

More particularly this invention is related to the manufacture of a gang of' staple-type nailing means made of sheet metal and adapted to be forcedly driven into wooden material and structures.

Heretofore, such articles of manufacture have been prevailingly made by separately forming such staples and by forming the gang by adhesively connecting a plurality of standard-sized staples in aligned and adjacent relationship. Such known method has been proved as not satisfying in the production of relatively big sized staple-like nailing means, mainly in relation with the weakness of the connection of the several staples into a gang adapted for use as a loading unit for nail driving device of the type referred to above. Some other embodiments of such gangs of nailing means have been proposed too, wherein the several nailing means included into a gang were formed from one piece of sheet metal and each connected the adjacent others by un-cut portions of said sheet.

Such prior articles of manufacture are subject to several objections, as known to those skilled in the. art to which this invention appertains. The known methods lead to a considerable waste of sheet material, for example, and the un-cut portions of material included between pairs of adjacent head portions of each nailing means included in the gang require an actual and positive cutting action for severing ofi each leading nailing means from the adjacent one.

It is therefore an object of this invention to provide a useful gang of this character wherein all nailing means are formed by sheet metal and each connected to adjacent others by un-cut portions of said sheet located at least at two spaced locations and wherein the said sheet metal in such locations is machined for easy detachment of the leading nailing upon the very same punching action of the hammer or nail driver included in a suitable conventionally constructed nail driving device of the type considered, ie to provide a gang of integrally constructed and connected nailing means not requiring cutting action preparatory of each nail driving operation.

Another object of this invention is to provide a new and advantageous gang of nailing means including a plurality of nailing means constructed from sheet metal and possessing improved nailing properties.

A furthervobject of this invention is to provide an improved method for producing a gang of nailing means of staple type of the character described, the said method providing a substantially complete exploitation of the sheet material in forming the gang therefrom.

I A still other object of the invention is to provide a new method for forming a gang of nailing means of the type described, wherein each actual leading nailing means may be readily detached from the adjacent one upon the nail driving stroke of a reciprocatory hammer of staple driving devices of the character considered.

Another object of this invention is to provide new and advantageous means and apparatus for producing such article of manufacture by such improved method.

These and other objects and advantages of this invention are in part obvious and in part will be made apparent as this description proceeds, and the features which are believed as new and characteristic of the invention will be in particular set forth in the appended claims. The invention itself, however, and the new features embodied therein, will be best understood from the following detailed description thereof, when read in conjunction with the accompanying drawings, forming an essential component of this disclosure.

In the drawings, FIGS. 1 to 4 inclusive illustrate the new gang of nailing means and the new features of nailing means which may be successively driven therefrom; FIGS. 5 and 6 illustrate certain detail-s of the sheet metal when machined in the steps embodied in the new method of the invention; and FIGS. 7 to 18 show some typical details of examples of an apparatus provided for carrying out such method. More particularly:

FIGURE 1 is a perspective view of a gang of nailing means and includes a leading means already detached from said gang upon a nail driving operation;

FIGURE 2 illustrates in enlarged scale the gang in cross-sectional view taken in the line 22 of FIG. 3;

FIGURE 3 shows the gang (including few nailing means only) in side elevation and in likewise enlarged scale; 7

FIGURE 4 is a sectional view taken on the line 444 of FIG. 3 and showing in greatly-enlarged scale some critical details of the gang of nailing means;

FIGURE 5 is a perspective view in somewhat enlarged scale of a sheet metal portion upon completion of certain steps of the method of the invention;

FIGURE 6 likewise illustrates same portion upon further steps of said method;

FIGURE 7 is a somewhat diagrammatical showing in vertical sectional view of a rolling apparatus provided for producing the material of FIG. 5;

FIGURE 8 illustrates in greatly enlarged scale a detail of such apparatus and the operation thereof;

FIGURE 9 is a somewhat diagrammatical side elevational View of a die-punching apparatus provided for carrying out certain steps of the method;

FIGURES l0 and 11 illustrate same apparatus in sec-' tional horizontal views in the directions and'on the lines indicated at 10-10 and l11'i, respectively, in FIG. 9;

FIGURE 12 is a somewhat diagrammatical sectional view of a further die-punching apparatus provided to complete the steps leading to the material of FIG. 6, and shown in cross sectional view taken on line l2i2 of FIG. 13;

FIGURE 13 shows the same apparatus in side elevation;

FIGURES l4 and 15 illustrate the details of the die means of the apparatus of FIGS. 12 and 13, shown in the directions and in sectional views taken as indicated at 1414 and 1515, respectively, in FIG. 13;

FIGURE 16 illustrates in enlarged scale a detail of a die-punching male member devised for producing a gang of nailing means as shown in FIGS. 1 to 4 inclusive, from a material. as shown in FIG. 6, when co-operating with a suitable female die as shown in FIG. 17;

FIGURE 17 shows an enlarged fragmentary sectional view taken on line 1'7-17 of FIG. 18;

FIGURE 18 shows the same female die in a fragmentary, elevational view from above.

Referring first to FIGS. 1 to 4 inclusive, there is shown a typical form of embodiment of a new gang of nailing means produced according to the invention, and generally indicated at in FIG. 1. Such gang is dimensioned to form a loading unit for a suitable conventionally constructed staple-type nail driving device including a magazine adapted to be loaded with such gang and means to feed the gang of staples longitudinally of the magazine and position the leading staple or nailing means 21 in the path of movement, diagrammatically indicated by arrow A in FIG. 1, of a reciprocatory driving hammer (not shown) to drive such leading nailing means particularly for use in joining parts made of penetrable material, such as wood, fiber, composition, or the like.

In FIG. 1 a single nailing means, indicated at 22, is also shown upon detachment thereof from the said gang 20, such detachment being supposed to have been produced by same driving movement A of driving hammer. Each single nailing means which may be successively separated from said gang includes a nail head and driving face forming cross portion 23 and two substantially parallel piercing elements or prongs forming leg portions 24. Furthermore, the tips of these piercing elements or prongs 24 are curved outwardly, with respect to the plane of the piercing elements, for the purpose of causing the piercing elements to enter or penetrate the parts to be joined or otherwise nailed at an angle to their point of entry.

Such portions 23 to 25 of the nailing means of the invention are integrally formed by cutting and punching processes from sheet metal, namely of steel or ironbased metal, and bent into a reinforcing rib forming substantially U-shaped cross-sectional shape therethrough, having an in-facing concave face. A typical cross-sectional shape of such either cross and leg portions 23 and 24 of each nail is illustrated in the leftward portion of FIG. 4 and includes a well rounded outer portion and sharpened in-facing edges to facilitate the penetration in driving-in the nailing means.

All nailing means included in each loading unit consisting of a gang of staples produced according to the invention are integrally formed from one blank of sheet metal and each nailing means is connected to adjacent ones by small sized and weakened un-cut portions of such blanks, at least at two spaced locations between any pair of adjacent nailing means. In the form of embodiment shown, there are one un-cut connecting portion at 26 (FIGS. 2 and 3) at the middle of said cross portion 23 and two symmetrically located un-cut portions 27 substantially mid-way on the said leg portions or prongs 24. In small sized gangs of nailing means produced according to the invention the said center connecting portion at 26 may be omitted without prejudice for the operatableness of the gang.

As shown in FIG. 3 and more particularly in FIG. 4 a substantial interval 28 exists between adjacent nailing means of the gang, except at the locations wherein the described connecting un-cut portions are provided. Such interval has been proved as very useful for prompt separation of the leading nailing means from the remaining part of the gang 20 (FIG. 1) preventing any possible interference or contact of the said leading nailing means 21 and of the driving hammer with the adjacent nailing means.

An important feature of the invention very effectively admits of a cutting of said plurality of piercing or nailing means into a gang from a blank so that a very substantial saving or also a nearly complete exploitation of material is obtained, that is to say, a very substantial increase in number produced per ton of sheet material used and so that the manner in which this cutting is performed also provides additional functional advantages that are to be particularly evidenced in the way the single nailing means are readily and safely detached each to the other upon the very driving stroke of the driving hammer, without subjecting said hammer and the other members of a conventionally constructed staple feeding and driving mechanism to undesirable stresses or unduly severe service conditions.

Such feature will be readily understood in its broader character with reference to FIGS. 5 and 6. A gang of staples as above described is produced from a blank consisting of a strip of sheet metal of suitable character and thickness, the Width of said strip corresponding to the length of one nailing means, developed into a plane, i.e. corresponding to the length of the cross portion 23 plus the lengths of both prongs 24. Such material as available in trade is then corrugated into the corrugated sheet 30 of FIG. 5, wherein each corrugation 31 thereof corresponds to one portion of material to be worked out in a single nailing means forming portion of the gang to be manufactured.

By further steps of the method of the invention the said corrugated blank 30 of FIG. 5 is then worked into the machined material 32 of FIG. 6, wherein the various parts of such material, which will form corresponding parts of the gang of nailing means and of the single nailing means integrally constructed thereinto, as shown in FIGS. 1 to 4 inclusive, are indicated by same reference numerals than in said latter FIGS. 1 to 4, accompanied by index for best understanding of the adaptation of the material to the scope of the invention.

The side edge portions of blank 30 are die punched or otherwise cut into tips 25 evenly provided at each corrugation and designed to form the tips 25 of each nailing means, and the deeper portions of each corrugation are pierced through to form groove-like cuts 28' extending cross-wise the blank except in selected locations at 26' and 27' to leave the desired un-cut portions 26 and 27, respectively, wherein the several nailing means remain integrally but detachably inter-connected in the blank 20 of FIG. 1. The outwardly directed curvature of tips 25 may be produced in punching step of forming same tips, or during the performance of the last steps of the method, which consists in bending lengthwise the blank, i.e. at right angle in respect to said cuts 28', to produce the desired blank 20 (FIG. 1) from the material 32 of FIG. 6. Arrows B in FIG. 4 indicate the direction and the location at which the said cutting or piercing through action should be exerted to produce the said cuts 28; the said FIG. 4 might be considered a sectional view of the material of FIG. 6 too, such material correspond-ing at any part thereof to the finished gang of FIGS. 1 to 3, except in relation with the bending of same material to form the various head and prong portions of the nailing means and the outwardly curved tips thereof.

In addition, during at least one of the steps of the method, and preferably during the corrugation of the commercial sheet material, the material is weakened, namely by pressure or partial piercing thereof, at the spaced lines defining the locations at which the said piercing through is to be successively performed, whereby the material will be weakened at locations 26' and 27' too, to improve the prompt breakage of connecting portions at 26 and 27 in the gang during the nailing means driving operation.

The above described various steps of the method of the invention may be performed by making use of differing processes of sheet metal workmanship known in the art, namely by rolling and/or die-punching procedures. In FIGS. 7 to 18 inclusive some examples of tooling and of apparatus which are believed to be particularly adapted for carrying out the invention are shown. Such means of manufacture are illustrated in their parts and components pertinent to the invention only, as being assumed that such means generally appertain to current knowledge of the art, both as to their structure and mode of operation.

As shown in FIG. 7, a commercially available flat sheet metal made strip 40' is fed in direction C between counter-rotating rolling tools 41 and 42 provided with outer toothed surfaces 43 and 44, respectively, in meshing relationship, to deliver the corrugated blank 30 of FIG. 5, upon rotation in direction E and F of such rotary rolling tools.

In FIG. 8 there is shown as such rolling operation may impart to the said corrugated material a corrugational shape and localized weakenings' adapted for the scope of the invention. The mating toothed surfaces 43 and 44- of such rotary tools are provided with rounded teeth 45 and respectively with sharp and. substantially cutting edged teeth 46 whereby the delivered corrugated material at 30 will include rounded surfaces adapted to form the ribbed nailing means alternatively located with sharply bent, half-cut and weakened portions wherein the said cuts 28' of FIG. 6 will be pierced through and wherein the small and'weak'connecting portions 26 and 27 will be left un-cut in the gang of nailing means of the invention, as shown in FIGS. 1 to 4. g

The pointed and piercing tips of the prongs of the several nailing means included into a gang may be pro duced for example making use of a die-punching apparatus of the type shown in FIGS. 9 to 11 inclusive, and arranged with a movable die 56' supported for vertical reciprocation including a downward cutting stroke on an apparatus structure sl'supportinga counter-die 52. Such counter-die 53 includes a. material seat forming upper surface 53 (FIGS. 9 and 10) having corrugations shaped to mating with the corrugations of the blank 30 of FIG. and end portions 54 shaped for precise fitting with cutting side portions 55 (FIGS. 9 and 11) of said movable die 50 for punchingly'cutting material from the side portions ofsaid corr-ugatedblank and producing the tapered tips 25' (FIG; 6) thereon.

FIGS. 12 to 15 inclusive illustrate an example of apedges of downwardly directed cutters on the lower face 65 of said movable piercing die 60 may freely enter upon piercing through the material seated on said counter-die upper face 64;

According to an important feature of the apparatus provided bythe invention; the said cutting edges on face 65 are interrupted by providing on said face 65 narrow parallel grooves and 67 (FIGS. 13 and 15) crossing at right angle said cutters at locations such to leave on the pierced through material the un-cut connecting portions indicated at 26' and at 27, respectively, in the material shown in FIG. 6 and designed to form the portions 26 and 27, respectively, at which the various nailing means in the gang 2% of FIG. 1 are integrally interconnected.

From what above and by a consideration of the accompanying drawings it is believed to be apparent that by making use of a rolling apparatus of the type shown in FIGS. 7 and 8 a corrugated material as shown in FIG. 5 may be produced, that such material may be provided with weakened lines (as indicated at 47 in FIG. 8) wherein interconnecting un-cut but readily breakable portions may be obtained, that by making use of proper punching, cutting and piercing apparatus, say such illustrated in FIGS. 9 to 15 inclusive, a material as shown in FIG. 6 may be produced, and that such production may be effectively carried out from a sheet metal blank so that a very substantial saving of material is obtained. As a matter of fact, it may be assumed that only the very small portions of sheet metal cut away in the piercing elements or prong tips tapering (namely performing by making use of the apparatus of FIGS. 9-11) will be deemed as waste material.

The last step of the process includes the bending of the material of FIG. 6 into a gang of nailing means as shown in FIGS. 1, 2 and 3. Such bending may beperformed by making use of a punching apparatus arranged with die means of the type shown in FIGS. 16 to 18, for example. FIG. 16 shows a male punching die '76 shaped to fit into the gang to be produced and to mate with a cavity 71 in a female counter-die 72. Such punching or stamping die means may be provided with tapered portions 73 and 74, respectively, designed to provide the above described outwardly curved tips 25 (FIGS. 1 to 3) of each nailing means integrally, formed in the gang 20.

While the invention has been heretofore described and shown but in one preferred form of embodiment thereof, it is intended that the invention is not limited not be taken as restrictive of the invention, as it is obvious that various modification either in articles of manufacture produced and in the method, process and means made use of for producing such articles may be resorted to by those skilled in the art to which this invention. appertains. -The above described punching apparatus provided for tips tapering and piercing through the material might be substituted by rolling type apparatus, for example, and/or the described corrugation and/or weakening of the blanks, performed as described with reference to the rotary apparatus of FIGS. 7 and 8, might be performed by making use of punching-type means too, if desired.

It is further believed to be evident that the present invention includes a plurality of advantageous features, and-it will'be understood that each of the new features described and shown and'any combination thereof may also find useful application in other formation and/or manufactureof nailing articles from sheet material and in other processes of producing same, differing from the ones described.

Without further elaboration, the foregoing will so fully explain the gist of my invention that others can, by applying current knowledge, readily adapt the same for use under varying conditions of service, without eliminating certain features, which may properly be said to constitute the essential items of novelty involved, which items are intended to be comprehended within the spirit and meaning of equivalent of the invention, and defined and secured to me by the following claims.

Having thus described the invention, what I claim as new and desire to have protected by Letters Patent is:

1. In a method ofproducing a gang of interconnected staples, comprising the-steps of corrugating a strip of sheet metal transversely to its elongation to form alternating ridge and groove portions in which said groove portions are bent to a smaller radius of curvature than said ridge portions to stress the material at said groove portions to a greater extent than the remainder of said strip; and subsequently piercing through said corrugated strip along spaced lines respectively extending along the bottoms of said groove portions except at spaced portions along said lines to leave spaced uncut portions integrally connecting adjacent ridge portions of said strip.

2. In a method of producing a gang of interconnected staples, comprising the steps of corrugating a strip of sheet metal transversely to its elongation to form alternating ridge and groove portions; compressing the material at the bottoms of said groove portions to provide a weak ened cross section at the bottom of each groove portion; and subsequently piercing through said corrugated strip along spaced lines respectively extending along the Weakened portions at the bottoms of said groove portions except at spaced portions along said lines to leave spaced uncut portions integrally connecting adjacent ridge por tions of said strip.

3. In a method of producing a gang of interconnected staples, comprising the steps of corrugating a strip of sheet metal transversely to its elongation to form alternating ridge and groove portions in which said groove portions are bent to a smaller radius of curvature than said ridge portions to stress the material at said groove portions to a greater extent than the remainder of said strip and simultaneously compressing the material at the bottoms of said groove portions to provide a weakened cross section at the bottom of each groove portion; and subsequently piercing through said corrugated strip along spaced lines respectively extending along the weakened portions at the bottoms of said groove portions except at spaced portions along said lines to leave spaced uncut portions integrally connecting adjacent ridge portions of said strip.

4. In a method of producing a gang of interconnected staples, comprising the steps of corrugating a strip of sheet metal transversely to its elongation to form alternating ridge and groove portions in which said groove portions are bent to a smaller radius of curvature than said ridge portions to stress the material at said groove portions to a greater extent than the remainder of said strip; and subsequently piercing through said corrugated strip along spaced lines respectively extending along the bottoms of said groove portions except at a plurality of portions along said lines which are symmetrically arranged with respect to a longitudial center line of said strip to leave spaced uncut portions integrally connecting adjacent ridge portions of said strip.

5. In a method of producing a gang of interconnected staples, comprising the steps of corrugating a strip of sheet metal transversely to its elongation to form alternating ridge and groove portions in which said groove portions are bent to a smaller radius of curvature than said ridge portions to stress the material at said groove portions to a greater extent than the remainder of said strip; subsequently piercing through said corrugated strip along spaced lines respectively extending along the bottoms of said groove portions except at spaced portions along said lines to leave spaced uncut portions integrally connecting adjacent ridge portions of said strip; serrating the side edges of said strip to provide opposite pointed ends at each ridge portion; and bending said strip along two parallel lines equally spaced from a longitudinal center line of said strip and at right angles to said corrugations.

6. In a method of producing a gang of interconnected staples, comprising the steps of corrugating a strip of sheet metal transversely to its elongation to form alternating ridge and groove portions in which said groove portions are bent to a smaller radius of curvature than said ridge portions to stress the material at said groove portions to a greater extent than the remainder of said strip and simultaneously compressing the material at the bottoms of said groove portions to provide a weakened cross section at the bottom of each groove portion; subsequently piercing through said corrugated strip along spaced lines respectively extending along the weakened portions at the bottoms of said groove portions except at a central portion of each line and two outer portions located at opposite sides and equally spaced from said central portion to leave spaced uncut portions integrally connecting adjacent ridge portions of said strip; serrating the side edges of said strip to provide opposite pointed ends at each ridge portion; and bending said strip along two parallel lines equally spaced from a longitudinal center line of said strip at distance smaller than the spacing between said central portions and said outer portions and at right angles to said corrugations.

7. In a method of producing a gang of interconnected staples, comprising the steps of corrugating a strip of sheet metal transversely to its elongation to form alternating ridge and groove portions in which said groove portions are bent to a smaller radius of curvature than said ridge portions to stress the material at said groove portions to a greater extent than the remainder of said strip and simultaneously compressing the material at the bottoms of said groove portions to provide a weakened cross section at the bottom of each groove portion; subsequently piercing through said corrugated strip along spaced lines respectively extending along the weakened portions at the bottoms of said groove portions except at a central portion of each line and two outer portions located at opposite sides and equally spaced from said central portion to leave spaced uncut portions integrally connecting adjacent ridge portions of said strip: serrating the side edges of said strip to provide opposite pointed ends at each ridge portion; bending said strip along two parallel lines equally spaced from a longitudinal center line of said strip at distance smaller than the spacing between said central portions and said outer portions and at right angles to said corrugations; and outwardly bending the outer end portions of each ridge portion.

References Cited by the Examiner UNITED STATES PATENTS 1,581,887 4/26 Taplin -17 1,733,506 10/29 Maynard 59-77 1,741,279 12/29 Bowman 85-49 1,793,960 2/31 Probert et a1 5971 1,942,249 1/ 34 Kleinschmit 5971 2,021,274 11/35 Vogel 85-17 2,033,613 3/36 Crosby 59-77 2,103,176 12/37 Randall 59'-77 2,128,443 8/38 Vogel 5977 2,242,967 5/41 Carlile 8517 WILLIAM J. STEPHENSON, Primary Examiner.

CARL W. TOULIN, CHARLES W. LANHAM,

Examiners.- 

1. IN A METHOD OF PRODUCING A GANG OF INTERCONNECTED STAPLES, COMPRISING THE STEPS OF CORRUGATING A STRIP OF SHEET METAL TRANSVERSELY TO ITS ELONGATION TO FORM ALTERNATING RIDGE AND GROOVE PORTIONS IN WHICH SAID GROOVE PORTIONS ARE BENT TO A SMALLER RADIUS OF CURVATURE THAN SAID RIDGE PORTIONS TO STRESS THE MATERIAL AT SAID GROOVE PORTIONS TO A GREATER EXTENT THAN THE REMAINDER OF SAID STRIP; AND SUBSEQUENTLY PIERCING THROUGH SAID CORRUGATED STRIP ALONG SPACED LINES RESPECTIVELY EXTENDING ALONG THE BOTTOMS OF SAID GROOVE PORTIONS EXCEPT AT SPACED PORTIONS ALONG SAID LINES TO LEAVE SPACED UNCUT PORTIONS INTEGRALLY CONNECTING ADJACENT RIDGE PORTIONS OF SAID STRIP. 